题目

The children vary considerably in the rate at which they learn these lessons. _____, we make the teaching plans different accordingly.A. Because of this reason                             B. It is becauseC. As a result of                                          D. For this reason 答案：D小陈同学用电池做电源，把漆包铜线缠绕在铁棒上制成电磁钉耙，通电后铁棒和铜线组成       ，可把地上的铁钉吸上来，断电时钉耙的       消失，所吸附铁钉脱落。请举出生活中类似应用的简单例子：                               。